12.4 Accumulating Text

Usually we copy or move text by killing it and yanking it, but there
are other convenient methods for copying one block of text in many
places, or for copying many scattered blocks of text into one place.
Here we describe the commands to accumulate scattered pieces of text
into a buffer or into a file.

M-x append-to-buffer

Append region to the contents of a specified buffer.

M-x prepend-to-buffer

Prepend region to the contents of a specified buffer.

M-x copy-to-buffer

Copy region into a specified buffer, deleting that buffer's old contents.

M-x insert-buffer

Insert the contents of a specified buffer into current buffer at point.

M-x append-to-file

Append region to the contents of a specified file, at the end.

To accumulate text into a buffer, use M-x append-to-buffer.
This reads a buffer name, then inserts a copy of the region into the
buffer specified. If you specify a nonexistent buffer,
append-to-buffer creates the buffer. The text is inserted
wherever point is in that buffer. If you have been using the buffer for
editing, the copied text goes into the middle of the text of the buffer,
starting from wherever point happens to be at that moment.

Point in that buffer is left at the end of the copied text, so
successive uses of append-to-buffer accumulate the text in the
specified buffer in the same order as they were copied. Strictly
speaking, append-to-buffer does not always append to the text
already in the buffer—it appends only if point in that buffer is at
the end. However, if append-to-buffer is the only command you
use to alter a buffer, then point is always at the end.

M-x prepend-to-buffer is just like append-to-buffer
except that point in the other buffer is left before the copied text, so
successive prependings add text in reverse order. M-x
copy-to-buffer is similar, except that any existing text in the other
buffer is deleted, so the buffer is left containing just the text newly
copied into it.

The command M-x insert-buffer can be used to retrieve the
accumulated text from another buffer. This prompts for the name of a
buffer, and inserts a copy of all the text in that buffer into the
current buffer at point, leaving point at the beginning of the
inserted text. It also adds the position of the end of the inserted
text to the mark ring, without activating the mark. See Buffers,
for background information on buffers.

Instead of accumulating text in a buffer, you can append text
directly into a file with M-x append-to-file. This prompts for
a filename, and adds the text of the region to the end of the
specified file. The file is changed immediately on disk.

You should use append-to-file only with files that are
not being visited in Emacs. Using it on a file that you are
editing in Emacs would change the file behind Emacs's back, which
can lead to losing some of your editing.

Another way to move text around is to store it in a register.
See Registers.